Firing mechanism for automatic firearms



Jan. 23, 1940. v, HOLEK 2,188,046

- FIRING MECHANISM FOR AUTOMATIC FIREARMS Filed Sept. 7. 1937 43 4o 2827 26 25 4o H Patented Jan. 23, 1940 UNITED STATES PATENT OFFICE VclavHolek, Zabovresky, Brunn, Czechoslovakia, assgnor to CeskoslovenskaZbrojovka, A. S., Brno, Brunn, Czechoslovakia, a, company ofCzechoslovakia Application September 7, 1937, Serial No. 162,735 InCzechoslovakia September 24, 1936 8 Claims.

This invention relates to firing mechanism for automatic firearms whichare adjustable for continuous firing and also for firing a single shot.

The chief object of the present invention is to provide an arrangementof the ring mechanism which will simplify the same not only with regardto its construction but also with regard to its manipulation.

According to the invention there is arranged on the trigger of thefiring mechanism an adjustable device which co-operates with the searand is operated by the trigger and controlled by means thereof onadjustment for continuous firing or for firing a single shot.

Owing to the utilisation of Vthe trigger not only for the operation ofthe said adjustable device but also for adjusting the latter, theauxiliary devices, which have hitherto been used and are separatelyoperated and require an independent zo' member for this purpose, aredispensed with. In

a further feature of the invention, the firing mechanism is speciallysimplified by an arrangement in which the device that operates the searis arranged on the trigger which carries out pushing and rotarymovements, and, in which arrangement, the Sear-operating device isoperated by means of the trigger during the pushing movement Whilst,during the rotary movement, it is controlled in such manner that it isadjusted either to a position for continuous ring or to a position forring a single shot.

In order that the invention may be clearly understood and readilycarried into effect, the same will now be described more fully, by wayof example, with reference to the accompanying drawing, in which:

Figure 1 is a longitudinal sectional View of ring mechanism embodyingthe invention, the parts being shown in the safety position;

m Figure 2 is a similar View to Figure l but showing the mechanismadjusted to a position for continuous firing;

Figure 3 is a cross-section taken on the line III-III of Figure 2;

Figures 4 and 5 are views similar to Figures 2 and 3, but showing themechanism adjusted to a position for firing a single shot;

Figures 6, 7 and 8 show the trigger button in sectional elevationlooking in the direction of the 5o arrow p, Figure 1, the buttonoccupying dilerent positions; and

Figure 9 is a plan View of the button.

Referring to the drawing, l denotes the trigger casing, the said casinghaving mounted therein,

55 on a pin 2, a two-armed sear, one arm 3 of which is provided with anaperture 4 and is loaded by a` spring 8, Whilst the other arm 5 of thesear extends into the path of the breech mechanism and, in the exampleshown, co-operates with a projection 6 on the breech block 1.

The trigger is constituted by a trigger rod I0 which is axiallydisplaceable and rotatably mounted in bearings II and I2 in the casingI. One end of the rod Ill is formed as a press-button I4 which isprovided With a projection I5 and facilitates the operation of thetrigger during the rotary movement thereof. The press-button Ill isprovided on the periphery thereof with an opening I6, Figure 9, whichmerges into two 1ongitudinal grooves I8 and I9 arranged on two sides ofan end face I1 and disposed 90 apart. A tooth or projection formed onthe bearing II of the trigger button engages in the opening I6.

Rockably mounted on the trigger rod I0 is a device Y which co-operates,on the one hand, with the sear and, on the other hand, with the breechmechanism, the said device permitting the firing of a single shot to beeffected. This device, which constitutes a so-called interrupter,consists of a yoke-like or other form of body which is mountedconcentrically on the trigger rod I0 and is provided with a transverseWall 26 having a bearing 21 for the trigger rod ID. The bearing 21 isformed in such manner that it enables the interrupter to be rocked. Thebody 25 is provided with arms 28 and 29. The arm 28 passes through anaperture I3 in the bearing I2 and co-operates with the arm 3 of thesear, whilst the arm 29, which terminates in a rounded head 30, projectsinto the path of the breech mechanism and co-operates with a projection3| on the."

breech block.

Upon adjustment into a position for continuous ring or for ring a singleshot, the interrupter is controlled by means which are arranged on thetrigger rod I0 and come into operationt during the rotary movement ofthe said rod. The interrupter then acts as a lever of the rst order onearm of which is in two parts of which the part 28 co-operates with thesear and the part 29 co-operates with the breech mechanism, whilst.' thebody 25, which co-operates with the controlling means arranged on thetrigger rod, forms y the second arm of this lever. The said controllingmeans consists of projections 36 and 31 which are formed on a disc onthe trigger rod and are disposed at 90 to each other. The projection 3Bco-operates with a surface 33 on the body 25 and the projection 31co-operates with a surface 34 also on the said body. The pushingmovement of the trigger rod is transmitted to the interrupter by meansof a ring 39 on which the interrupter, which is loaded by the spring 46,bears by means of the wall 26.

On a square part IIJ' of the trigger rod I there is displaceably mounteda sleeve 4B or the like which is provided with a ring 4I having aprojection 42 which, in the safety position of the firing mechanism,co-operates with a projection 43 on the sear. The sleeve 4I) is providedwith adjusting means for the ring mechanism and, for this purpose, hason its end face a radial tooth 44 which co-operates with radial grooves45 formed on the adjacent end :face of the bearing I2.

Bearing against the ring 4I on the sleeve 4I) is one end of a spring 46which, with its other end, loads the interrupter and thus forms not onlythe returning spring of the interrupter and of the trigger rod duringthe pushing movement of the recoil, but also a 'resilient stay for theinterrupter during its rocking movement and restores the interrupter toits original position after it has been rocked.

'I'he operation of the firing mechanism is as follows:

When the firing mechanism is in the position shown in Figures l, 6 and9, the tooth 2i! is opposite the end face of the projection Il on thebutton I4 on the trigger rod, so that the pushing movement of thetrigger rod Ill and the operation of the sear are prevented. When thenring mechanism is in this position, the projection 42 on the sleeve 41Bis located beneath the projection 43 on the arm 5 of the sear, so thatthe sear cannot be rocked. The firing mechanism is locked in thisposition.

On rotating the button I4 in the bearing II into the position II shownin Figure 7, the projection 35 on the disc 35 bears on the upper surface33 of the body 25, Figure 3, and the interrupter is rocked so that thearms 28 and 29 thereof are lowered as shown in Figure 2. When thetrigger button is in this position, the projection 23 is opposite thegroove I9 so that there is no interference with the movement of thetrigger rod Iii when the button I 4 is acted upon in the direction ofthe arrow p, Figure l. 'Ihe trigger rod is displaced, compresses thespring 46 and takes with it the interrupter, the arm28 of which strikesthe arm 3 of the sear and thus rocks the sear. In this way, the breechmechanism is released and is moved in the direction of the arrow q,Figure l, under the action of the compressed projecting spring and ashot` is fired. The arm 2B of 'the interrupter keeps the Sear in therocked position as long as the finger of the operator presses on thetrigger button. 'Ihe arm 5 of the sear does not extend into the path ofthe breech block and therefore there is no interference with themovement of the said block. The gun is set with the ring mechanism forautomatic firing (series ring).

When the trigger rod is located in the position shown in Figures 4, 5and 8, the gun is adjusted for firing a single shot. The firingmechanism is adjusted in this position by rotating the button I4 on thetrigger rod III. Upon rotation of the button I4, the groove I3 comesopposite the tooth 2l), so that the pressing of the trigger is renderedpossible. During the rotary movement of the trigger rod I6, theprojection 3l on the disc 35 presses on the lower surface 34 of the body25, so that the interrupter is rocked in such manner that the head Siion the arm 29 enters the path of movement of the projection 3i on thebreech block '1. By pressing on the trigger, the trigger rod I0 isdisplaced and takes the interrupter with it, the arm 28 of which rocksthe sear which in turn releases the breech block for forward move- 5ment and iiring is effected. During the forward movement of the breechblock, the projection 3| thereof strikes the rounded head 35 of theinterrupter and presses it downwards in opposition to the action of thespring 46 so that the arm 28 10 cornes opposite the aperture 4 in thearm 3 of the sear. Since the sear is pressed by the action of the spring3, it is rocked back into the original position, the outer end of itsarm 5 entering the path of movement of the breech block which it 15holds securely after the recoil has taken place. For ring the next shot,it is necessary first to release the trigger, during which movement theinterrupter is, by the action of the spring 46, re-

turned to the position shown in Figure 4, and 20 a slidable trigger rod,a sear cooperating with=`25 said trigger rod, an interrupter pivotallymounted on said trigger rod cooperating with said sear and said breechblock, means for rotating said trigger rod and cooperating means onsaid'trigger rod and said interrupter to cause a pivoting30 of saidinterrupter upon a rotation of said trigger rod in order to set saidtrigger mechanism for continuous or single fire.

2. A trigger mechanism for automatic firearms vhaving a reciprocatingbreech block comprising 35 a slidable trigger rod, a sear cooperatingwith said trigger rod, an interrupter pivotally mounted on said triggerrod, an arm'on said interrupter cooperating with said sear, a second armon said interrupter cooperating with said breech .40

block, means for rotating said trigger rod and cooperating means on saidtrigger rod and said interrupter to cause a pivoting of said interrupterupon a rotation of said trigger rod in order to set said triggermechanism in position for 45 safety, continuous or single fire.

3. A trigger mechanism for automatic firearms having a reciprocatingbreech block comprising a slidable trigger rod, a sear cooperating withsaid trigger rod, an interrupter pivotally mounted on, 50

said trigger rod, two control surfaces on said interrupter displacedsubstantially 180 from each other, cooperating with said sear and saidbreech block, means for rotating said trigger rod to said predeterminedpositions and cooperating means` 5ron said trigger rod and saidinterrupter to cause a pivoting of said interrupter upon a rotation ofsaid trigger rod in order to set said trigger mechanism for safety,continuous or single're.

4. A trigger mechanism for automatic iirearmsno having a reciprocatingbreech block comprising a slidable trigger rod, a sear cooperating withsaid trigger rod, a sleeve loosely mounted on said trigger rod so as topivot thereon, two control surfaces on said sleeve displacedsubstantially 180165 from one another cooperating with said sear andsaid breech block, means for rotating said trigger rod and cooperatingmeans on said trigger rod and said sleeve for pivoting said sleeve upona rotation of said trigger rod in order to set said trigger mechanism inthe safety position or for continuous or single re.

5. A` trigger mechanism for automatic firearms having a reciprocatingbreech block comprising a slidable trigger rod, a sear cooperating withsaid* trigger rod, an interrupter pivotally mounted on said trigger rodcooperating with said Sear and said breech block, means for rotatingsaid trigger rod, a disc xed to said trigger rod having projectionsthereon relatively displaced about 90, a pair of surfaces on saidinterruptor relatively displaced about 180 cooperating with saidprojection to cause a pivoting of said interrupter upon a rotation ofsaid trigger rod in order to set said trigger mechanism for continuousor single re. l

6. A trigger mechanism for automatic Firearms having a reciprocatingbreech block comprising a slidable trigger rod, a sear cooperating Withsaid trigger rod, a sleeve member loosely mounted on said trigger rod soas to pivot Within predetermined limits thereon, two arms mounted onsaid sleeve, one of said arms cooperating With said sear and the otherarm cooperating with said breech block, a fixed ring on said trigger rodbearing against one face of said sleeve, resilient means bearing againstthe other face of said sleeve, means for rotating said trigger rod andcooperating means on said trigger rod and said sleeve to cause apivoting of said sleeve and said arms upon a rotation of said triggerrod in order to set said trigger mechanism for continuous or single nre.

'7. A trigger mechanism in accordance with claim 6 in which an abutmentis provided for said resilient means so as to return said trigger rod tothe initial position after a sliding movement thereof and said resilientmeans thereby forming a recoil spring for said trigger rod and a supportfor said sleeve.

8. A trigger mechanism for automatic firearms having a reciprocatingbreech block comprising a slidable trigger rod, a pivoted searcooperating with said trigger rod having a recess therein, aninterrupter pivotally mounted on said trigger rod, an arm on saidinterrupter cooperating with said Sear, a second arm on said interruptercooperating With said breech block, means for rotating said trigger rod,cooperating means on said 'trigger rod and said interruptor to cause apivoting of said interrupter upon a rotation of said trigger arm inorder to set said trigger mechanism for continuous or single fire andWhen said trigger mechanism is set for single re said arm cooperatingwith said sear passes through said recess so as to interrupt thecooperation between said Sear and said arm while said interrupter ispivoted by said breech block acting upon said second arm.

VCLAV HOLEK.

